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Electron-phonon coupling induced pseudogap and the superconducting transition in Ba0.67K0.33BiO3

A. Chainani·T. Yokoya·T. Kiss·S. Shin·T. Nishio·H. Uwe
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Abstract

We study the single particle density of states (DOS) across the superconducting transition (Tc = 31 K) in single-crystal Ba0.67K0.33BiO3 using ultrahigh resolution angle-integrated photoemission spectroscopy. The superconducting gap opens with a pile-up in the DOS, Delta(5.3 K) = 5.2 meV and 2Delta(0)/kBTc = 3.9. In addition, we observe a pseudogap below and above Tc, occurring as a suppression in intensity over an energy scale up to the breathing mode phonon(~ 70 meV). The results indicate electron-phonon coupling induces a pseudogap in Ba0.67K0.33BiO3.

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A. Chainani, T. Yokoya, T. Kiss, S. Shin, T. Nishio, H. Uwe. 2001-06-04. Electron-phonon coupling induced pseudogap and the superconducting transition in Ba0.67K0.33BiO3. https://doi.org/10.1103/physrevb.64.180509

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